Hand microphone and switch



Oct. 18,1949. w. E. GILMAN ETAL 2,435,273

HAND MICROPHONE AND SWITCH Filed March 31, 1945 5 Sheets-Sheet l fi? %27Z 2'0 7'5 (1126 5' 2492" Z. 5(2)][071 Oct. 18, 1949. w. E. GILMAN EI'AL HAND MICROPHONE ND SWITCH Filed March 51, 1945 5 Sheets-Sheet 4 Oct. 18, 1949. w. E. GILMAN ETAL 2,485,278

HAND MICROPHONE AND SWITCH Filed March 31, 1945 5 Sheets-Sheet 5 Patented Oct. 18, 1949 UNITED STATES PATENT OFFICE HAND MICROPHONE AND swrron tion of Illinois Application March 31, 1945, Serial No. 585,910

11 Claims.

This invention relates to transducers, and particularly to hand-held microphone devices.

Where a microphone is to be used in situations that require ready movement of the microphone, so as to make it impractical to utilize a conventional support or microphone stand, it has been customary to provide what has been termed a hand-held microphone that may be laid upon a table, the floor, or any other convenient shelflike surface when not in use, and which is grasped and held in the hand of the operator when the microphone is to be used. Hand-held microphones are, of course, intended for use in a close-talking relationship, and for this reason most hand-held microphones are highly directional in character, and in the use of hand-held microphones as heretofore constructed, the inherent diificulties experienced in handling and orienting the microphone, so as to insure impingement of the sound directly on the diaphragm of the microphone, have resulted in faulty transmission as well as objectionable delays in transmission, and to enable such diificulties to be avoided and eliminated is an important object of this invention.

Further objects related to the foregoing are to enable microphones to be so constructed that the user may quickly and easily grasp a microphone in such a manner that orientation of the microphone may be accomplished easily and accurately and without loss of time so that in a practical sense the microphone is self-orienting, to enable microphones to be so constructed and arranged that they may be readily grasped in the hand of the user in such a position that the user may readily and easily determine the location of the sound receiving openings of the microphone, and to enable the connector cord that extends from the microphone to contribute to the self-orienting properties or characteristics of the device. A more specific object of the invention is to enable microphones to be embodied in a relatively long and narrow form so that the body that is thus aiforded may be readily grasped in the hand of the user, and a further and more specific object is to so locate the sound receiving openings of such a microphone at one end of an elongated :body that is adapted to be grasped in the hand of the user so that when this body is thus grasped, the user will at once know that the sound receiving openings of the microphone are located in a particular end of the body.

In those instances where the user may be required to support a hand-held microphone in an operating position for long periods of time it is highly desirable that the users arm and hand be disposed in a natural or normal position so as to thereby avoid strain and fatigue, but in hand-held microphones as heretofore constructed it has been impossible to attain this desirable result. Thus, in prior hand-held microphones, the form and relationship of the parts has invariably required that the user grasp and support the microphone with the palm of the users hand faced toward the users mouth. This required twisting of the hand and lower arm to a strained and unnatural position, and as a result it has been found that objectionable fatigue and strain are imposed upon the user. It is therefore a further object of this invention to enable hand-held microphones to be supported in an operative relation to the users mouth while the users hand and arm are disposed in a natural or normal holding position. A related object is to enable such a hand-held microphone to be grasped in a normal encircling relation by the hand of the user .and to be supported in the desired operative relation to the users mouth while the thumb-side of the hand is disposed adjacent to the mouth.

In many uses of hand-held microphones, it is customary to embody a control switch as a part of the microphone so that by manipulation of this control switch, the operator may render the microphone or the associated transmitter, or both, operative or inoperative at will, and a further object of the present invention is to simplify the operation of such a control switch as embodied in a microphone. Another and related object is to embody control switch means in a microphone in such a manner that the switch may be readily operated by the user as soon as the microphone is picked up in a normal manner. A further object is to enable a microphone to be constructed in an elongated form adapted to be grasped in the hand of the user and to locate the switch control member on the side of the elongated body so that the control switch may be readily operated merely by squeezing the elongated member as it is normally grasped in the hand of the user. Where communications equipment such as a microphone is to be used in warm and humid climates, it is essential that switch means as well as the other electrical elements of the microphone be effectually sealed against the entrance of water or water vapor, and to enable this to be accomplished in a simple and expeditious manner is a further object of the present invention. Another object related to the foregoing is to enable a microphone and a control switch therefor to be so mounted and related that a conto enable a microphone, a control switch means and an impedance matching transformer to be so related and housed as to protect the operative electrical elements thereof against water or water vapor.

When hand-held microphones of the character to which the present invention relates are in service in the field, it often becomes necessary to replace or repair some of the parts thereof, and particularly, it becomes necessary to replace the connector cord whereby the microphone is connected to the transmitting or other related apparatus, and to facilitate and simplify such repair or replacement operations is a further object of this invention.

In the event that hand-held microphones of the kind to which this invention relates are to be used in tropical climates, the electrical elements thereof must be effectually sealed against the action of water and water vapor, and to effect such sealing of the parts requires exceptionally skilled workmen. Therefore it is desirable that this sealed relationship be maintained at all times, and that the sealed relationship be effected in such a manner that the usual servicing operations may be performed without disturbing the sealed relationship of the major parts of the device, and to enable this to be accomplished is another object of the invention. A more specific object is to mount the microphone element of a handheld microphone device in such a relation that it may be readily removed from a sealed relationship for repair or replacement, and another and related. object is to aiford a hand-held microphone device embodying terminal means and switch means in such association with a microphone that either the microphone or the connections to the terminals may be repaired or replaced without disturbing the sealed relationship of the switch means.

When a connector cord is extended into the casing of a hand-held microphone or the like so as to connect the wires of the cord to terminal means within the housing, it is desirable that a seal be afforded about the connector cord so as to prevent entrance of water or water vapor into the space where the wires are connected to the terminal means, and to enable this to be accomplished in a simple and effective manner is still another object of the present invention. Other and further objects related to the foregoing are to enable a connector cord to be firmly gripped at the point where such a cord enters a terminal chamber of a hand-held microphone device or the like, thereby to prevent endwise withdrawal of the cord, and to enable such a gripping of the cord to be accomplished without twisting of the connector cord. thereby to avoid tension on the connections between the wires and the terminals. More specifically it is an object to provide a releasable gland for embracing a connector cord at the point where such a cord enters a terminal housing or the like, and to enable such a gland to be tightened by means of a screw threaded member that is so associated with the other elements of the gland that the desired sealing and gripping action is attained without imparting rotative or twisting movement to the connector cord.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show preferred embodiments and the principle thereof and what we now consider to be the best mode in which we have contemplated applying that principle. Other embodiments of the invention embodying the same or equivalent principle may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings,

Fig. 1 is a perspective view of a hand-held microphone embodying the features of the invention, the hand-held microphone being shown in an operative relationship toflthe mouth of a user;

Fig. 2 is a longitudinal sectional view shown at full scale and illustrating the relationship of the microphone device to one form of noise shield that may be used in association therewith, the noise shield having been rotated slightly with respect to the position shown in Fig. 1;

Fig. 3 is an end elevational view of the noise shield;

Fig. 4 is an enlarged front elevational view of the microphone device with the noise shield removed;

Fig. 5 is a side elevational view of the microphone shown in Fig. i;

Fig. 6 is an end elevational view of the upper end of the microphone device shown in Fig. 4;

Fig. '7 is a longitudinal sectional view taken on an enlarged scale along the line 'l-l of Fig. 4;

Fig. 8 is a sectional view taken substantially along the line S8 of Fig. 7 and showing the manner in which the control switch means and the other elements of the microphone are mounted in one section of the casing;

Fig. 9 is a View similar to Fig. 8 and taken along the line 99 of Fig. '7 so as to show the other section of the casing and the manner in which the switch control member is mounted in this section of the casing Fig. 10 is a sectional view taken substantially along the line |U--I U of Fig. 4;

Fig. 1-1 is a sectional view taken substantially along the line I l-l I of Fig. 4;

Fig. 12 is 'a sectional view taken substantially along the line |2-l2 of Fig. 9 and illustrating details of the retaining ring and the transducer terminals;

Fig. 13 is a View taken in section substantially along the line I 3l 3 of Fig. 12;

Fig. 14 is a side elevational view of one form of microphone unit that may be utilized in the hand-held microphone of the present invention;

Fig. 15 is a longitudinal sectional view taken substantially along the line l5|5 of Fig. 14;

Fig. 16 is an endelevational view of the soundreceiving end of the microphone shown in Fig. 14;

"Fig. 17 is a transverse sectional view substantially along the line Hl1 of Fig. 15; and

Fig. 18 is an enlarged fragmental cross sectional view taken substantially along the line I8l8 of Fig. 16 and illustrating the manner in which the electrical connections are established between the voice coil and the terminals of the microphone.

For purposes of disclosure the invention is herein illustrated as embodied in a hand-held microphone device-20 that has its connector cord 2i extended from one end thereof while the sound-receiving or sound sensitive means 22, including a noise shield 23, are arranged at the other end thereof was to face axially away from the end to which the cord 2i is connected. The hand-held microphone device 20 of the present invention has the body thereof constructed in an elongated form and of such size and dimensions that the device may be readily grasped in the users hand, as shown in Fig. 1, and in accordance with certain aspects of the invention, control switch means are aiforded within the body of the device and are operable by laterally projecting switch operating means 24 extended along one side of the body of the device so as to be readily engageable by a portion of the users hand in any rotative relationship in which the device may be grasped. When the microphone device is thus grasped, it may be readily and easily supported with the sound sensitive means 22 and the noise shield 23 in an operative relationship to the users mouth, as shown in Fig. 1, and the switch operating means 24 may be operated at will by a mere contraction or squeezing action of the hand.

In providing the handheld microphone device 20 of the present invention, a sectional housing 25 that is preferably of generally cylindrical external form is made from a rigid insulating material such as Bakelite to afford elongated sections 25A and 253 that are separable substantially in a central longitudinal plane indicated at 25C in Fig. 5 of the drawings. The sections 25A and 25B are held together by securing means such as a self-tapping screw 28 that is extended through a bore 29 in the section 25B and is tapped into a bore 30 in the section 25A, as shown in Fig. 7 of the drawings, and when the screw 28 is in its final position, the head thereof is located within a clearance recess 3| formed in the section 253. After the sections 25A and 25B are placed in their assembled relationship as shown in Fig. 7 of the drawings, the opposite ends thereof are covered by end caps and 36 that are made from metal and are of generally cup-shaped form so as to be movable in an endwise direction into an encircling relationship with respect to the opposite end portions of the casing 25.

The end of the casing 25 that is embraced by the end cap 35 is so formed as to afford a mounting chamber 46 within which a microphone unit 4| is positioned, and the chamber 4!) is afforded by matching recesses formed in the casing sections 25A and 2513. The recess 4|! opens outwardly or longitudinally through the end of the casing 25 so that when a microphone unit 4| is disposed in position within the chamber 46, the sound-receiving openings 42 of the microphone unit may face outwardly toward soundreceiving openings 43 formed in a dome-shaped central portion 35A of the end wall of the end cap 35.

The chamber 4|) terminates in a bottom surface 44 that constitutes one side of a division wall 45 that separates the chamber 4!] from another mounting chamber that is formed in the casing 25 by matching recesses 56A and 563 formed respectively in the sections 25A and 2513. The mounting chamber 56 constitutes the chamber in which associated electrical elements are to be disposed, and in the present instance such associated electrical elements include an impedance matching transformer 5| and switch means 52 that are operable by the switch operating means 24. The impedance matching transformer 5| and the switch means 52 are associated with each other and with the connector cord 2| and the microphone unit 4| in a manner which will hereinafter be described in detail, and circuits are extended therefrom to terminal means 55 that are housed within a terminal chamber 56 that is provided by. the end cap 36. Hence, when the end cap 36 is removed from the position shown in Fig. 7, the terminal means 55 are exposed for such servicing operations as are required, and this may be accomplished without disturbing the other elements of the device.

In affording the terminal chamber 56, the section 253 of the casing is terminated at 51 just within the edge of the end cap 36, while the section 25A has an integra1 extension 25 that serves as a mounting for the terminal means 55 and also as means for enabling the end cap 36 to be seecured in the desired position on the end of the casing 25. Thus, the extension 25' of the casing section 25A has a laterally facing recess 60 formed therein and this recess is shouldered at 6| to afford a mounting face for an arm 62 of an angle bracket 63. The arm 62 of the angle bracket, in effect, comprises a relatively large plate having an opening 62' formed therein so as to open into a chamber 60A that in reality constitutes an extension of the recess 6|). The chamber 60A has an opening or passage 65 extended through the material of the casing section 25A and into the recess 50A, and within the recess 50A the passage 65 merges into a longitudinal groove 65A formed along the bottom of the recess 50A so that wires may be extended through the recess 50A beneath the transformer 5| and switch means 52. Thus it is possible to extend connecting wires from the electrical means within the chamber 50 to the chamber 60A, and within this chamber, such wires are connected to electrical terminals 69 that are carried on a fibre insulating plate 16 that covers the opening 62 in the plate 62. The terminals 69 are secured in place on the insulating terminal plate ID by integral tubular rivet portions or extrusions and the necessary electrical connection between a wire and a terminal 69 is effected by passing the wire through the tubular rivet portions and soldering the same so as to close the opening in the tubular rivet as indicated at 69 in Fig. 8 of the drawings. The insulating plate 10 and the mounting plate 62 are secured in position on the shoulder 6| by drive-screws II, or self-tapping screws may be used in place of drive-screws in this instance as well as the other cases where drive screws have been shown or described. The mounting bracket 63 has a second arm 15 that serves as a support for a connecting gland 16 that includes means for clamping the end cap 36 in place and also includes means for clamping the connector cord 2| in the desired position at its point of entry into the terminal chamber 56, as will hereinafter be described in detail.

In accordance with the present invention, all of the electrical elements that are permanently mounted in the device are mounted on the section 25A of the casing so that assembl of the device is thereby facilitated. Thus the transformer 5| and the switch means 52 are permanently mounted within the recess 50A in the casing section 25A, as shown in Figs. 7 and 8, and this mounting is-accomplished in such a manner that when the two casing sections 25A and 25B are assembled, the switch means 52 are disposed in an operative relationship with respect to the switch operating means 24. Thus the switch means 52, which in thepresent instance includes two switches 52-| and 52-2, are disposed in the recess 50A near the end thereof that is adjacent to the chamber 60A. Such switch means may of course take many diiferent forms, but as herein shown, the switch means are of the over-center type. Thus the switch means include a mounting block 80 seated in the deep portion'of the recess 50A and having a mounting bar'8I .along its upper edge, and the mounting bar 8l has'its ends rested upon pedestals '82 formed opposite sides of the recess 50A on the shoulder 82' so that securing means such as drive-screws 03 may be extended through the ends 8i and into the pedestals 82 so as to secure'the switch means '52 in place. Each switch of the switch means 5 includes a stationary contact 84 that is .in the form of a blade extended through the mounting block 80 to expose one end 84' thereof for connection with a wire that is to be associated with the switch. Each switch also includes a movable contact blade 85 that is also extended through the block 80 as at 85 to afford terminal means for connection with the wire or the like. The movable contact 85 is adapted to be bent or shifted from the normal open position shownin Fig. 7 to a closed position wherein it engages the stationary contact 84, and this is accomplished by an over-center spring 81 that has one end thereof pivoted t the end of the movable contact 85 while the other end thereof is pivoted to an operating spring arm 88 mounted in the mounting block 80.

When the operating spring arm 88 is moved'to the left in Fig. '7, the movable switch contact 85 is also forced to the left until the back face thereof comes into contact with an abutment plate 89 that is carried in the mounting block 80, and after the movement of the arm 88 has progrossed to such an extent as to move the upper end of the spring 81 substantially to the left beyond the position of the lower end of the spring 81, the over-center action of the spring causes the movable contact 85 to be quickly shifted to the right and into its closed relationship with respect to the stationary contact 84. Similarly, when th operating spring arm 88 is allowed to return in a right-hand direction toward the position shown in Fig. '7, the spring 81 again moves through its center position so as to quickly move the movable contact from its closed position to its open position. The operation of the spring arm 88 is accomplished by the switch operating means 24 in the manner that will hereinafter be described in detail.

The impedance matching transformer 5I is disposed within the recess 50A in the casing section 25A in the space between the switch means 52 and the wall 45, and such mounting is accomplished by mounting straps 95 that are secured as by rivets 95' to opposite ends of the core or laminations of the transformer 5|. The other ends of the mounting straps are disposed on the ends of what may be termed pedestals 96 formed at adjacent ends of the ledges 82, and drive screws 91 secure these ends of the straps '95 on the tops of the pedestals 96. One of the windings of the transformer 5| has the leads 98 thereof associated with the microphone unit M and in accomplishing such association, the leads 98 are extended to a pair of terminals I00 mounted in the recess 50A of the section 25A. The terminals I 00 are secured on the lower face of the wall 45 as viewed in Figs. '7 and 8 by means such as rivets IOI that extend through the wall 45. The upper ends of the rivets I 0| are arranged to secure terminal brackets I02 in position within recesses I03 formed in the upper face 44 of the wall 45, as will be evident in Figs. '7, 8 and 12 of the drawings. The rivets IOI extend the electrical circuits from the respective terminals I00 to the bracketsl02, and these brackets I02 have angularly related terminal arms I05 formed thereon as shown in Figs. 7 to 12 so as to extend upwardly along one side of the recess 40 in spaced grooves I06. The terminal brackets I02 are made from a spring material such a phosphor bronze so as to enable efficient contact to be made with the connecting terminals I01 of the microphon unit 4|, and the upper ends of the terminal arms I05 are in position for engagement by such connecting terminals I01 when a microphone unit M is moved in an endwise direction into position in the chamber 40 as will hereinafter be explained.

Leads I 08A and N813 from the other winding of the transformer 5| are extended toward the bottom of the recess 50A and into the groove 65A, and are then extended within the groove 55A toward the passage 65. In the present instance the wire 108A is extended directly through the passage 65 and into the chamber 60A, and is connected to an appropriate one of the terminals 69. The other lead I08B however is extended beneath the mounting block and is then extended out of the groove 65A and to the stationary contact84 of the switch 522, to which it is connected as by soldering. The other or movable contact 85 of the switch 522 has a wire 109A connected thereto as by soldering, and this wire is led into the groove 65A and through the passage 65 and into the chamber 60A where it is connected to another one of the terminals 59. Wires I09C and I09D are connected to the other two terminals 09, and are extended through the passage I55 from which they are further extended into the recess 50A and are connected respectively to the terminals 84 and 85 of the switch 52I. Thus, the closure of the switch 522 closes circuit from two of the terminals 89 through one winding of the transformer 5 I, thereby to control circuit to the microphone unit 4I, while closure of the switch 52I completes circuit between the other two terminals'69. Such operation of the switch 52I may be utilized to cause operation of relay means or the like for governing operation of an associated transmitter or other related equipment.

The switch operating means 24 are mounted on the other section 25B of the casing so as to cooperate with the spring arms 88 in effecting operation of the switches 52-I and 522. Thus, the section 25B of the casinghas an elongated slot I I0 formed therein so as to extend longitudinally of the casing, and an operating lever I I I formed from a rigid insulating material such as Bakelite is disposed in this slot so as to extend outwardly beyond the side of the casing section 25B. The operating lever arm III is supported on a mounting plate I I2 that has ears I I3 formed thereon in spaced relation so that a pivot lug II4 formed on the lower end of the arm III as shown in Fig. '7 may be disposed between the ears H3. A pivot pin II5 extends through the lug I I4 and into the ears I I3 so that the arm I II may be pivoted about the axis of the pivot pin H5. The mounting of the lever arm IH in the slot H0 is in the present case accomplished in such a manner as to seal the openin or slot IIO against the entry of water or water vapor. This is accomplished through the provision of a sheath I20 that is molded from a flexible material such as rubber so as to embrace the side surfaces and the outer surface of the lever arm III and the sheath also is formed to afford a flange I2'I at the innermost edgeof the sheath, and this flange HI is clamped against a shoulder I22 formed about the inner edge of the slot I I0. Such clamp- I ing action is in the present case eifected by the bordering edge of the mounting plate H2, this bordering edge being secured against the shoulder I22 by drive-screws I24, as will be evident in Figs. 7, 9 and 11 of the drawings. The lever arm III has a switch operating finger I25 formed thereon that extends through an openin I26 formed in the mounting plate H2, and as will be evident in Figs. 9 and 11, this operating finger I25 is of such a width that it will engage both of the operating spring arms 88 of the two switches; The spring arms 88 act on the lever arm III to normally maintain the arm I I I in its outwardly projected relationship of Fig. 7, thereby to maintain the switch .means 52 normally open, and the strength of the spring action of the arms 88 is such that the switch means 52 will not be inadvertently closed as for instance when the device is laid down with the switch operating means 24 in a downward position. Thus when the user applies a positive inward pressure to the sheath I20, the arm III is pivoted about the axi H5, thereby to force the spring arms 88 in a switchclosing direction. In order that damage to the switch means may be avoided, a stop finger I28 is provided near the free end of the lever arm III, and this stop finger is arranged to engage the mounting plate H2 when the lever arm III has been moved for a distance suificient to cause closure of the switch means.

When a hand-held microphone of the charactor to which the present'invention relates is to be utilized in a tropical climate, it is desirable that all of the electrical elements of the device be sealed against the entry of water or water vapor, and hence the association of the elements of the microphone device of this invention is ac complished in such a manner as to efiect such desirable sealing of the electrical elements. It is particularly desirable that the electrical means included within the chamber 50 be permanently sealed against the entry of Water or water vapor, and insofar as the switch operating means 24 are concerned, it will be evident that the provision of the sheath I2II serves to effect this result. In this connection however, it may be pointed out that a suitable sealing compound or adhesive means may be applied to the shoulder I22 before the sheath is clamped in place against this shoulder. Another path along which water or water vapor might tend to enter the chamber 50 is aiforded along the separation line or plane C, and to simplify the provision of an effective seal between the two sections 25A and 25B, an interlocked arrangement is provided about at least a portion of the border about the cavities that provide the chamber 50. Thus as shown in Figs. '7, 8, 9 and 11, a continuous ridge or rib I30 is provided about the sides and lower edge of the cavity 50A that is formed in the section 25A. this rib being bordered at its outer edge by a flat surface I3I that lies in the plane of separation 25C. The section 253 has a flat surface I32 that is adapted to have flat surface engagement with the bordering surface I3I of the section 25A, and inside of the bordering surface I32, the section 25B has 'a continuous groove I33 into which the rib I30 is adapted to fit, as will be evident in Figs. 7 and 11. In the portions of the two sections 25A and 253 that afford the upper end of the casing, the sections 25A and 25B are provided respectively with flat surfaces I34 and I35 that have a flat surface engagement when the two sections are in their assembled relationship. In

the course of assembly of the two parts or sections 25A and 253, it is preferable to apply a suitable adhesive or sealing compound along the sides of the cavities that form the chamber MI, and in a continuous line about the borders of the cavities 50A and 50B so as to cover at least a portion of the surfaces that are to be placed in abutting relationship, as indicated in Fig. 11, and hence when the two sections are drawn together by tightening of the self-tapping screw 28, the sealing compound will provide an effective and continuous seal about the entire border portion of the chamber sill and along the bottom and sides of the chamber 43. The seal that is thus afforded is maintained by the interlocking action of the rib I30 and the groove I33 which are in turn held in such interlocking relation by the screw 28.

It will be recalled that the chamber 50 communicates with the chamber 60A through a passage 65, and hence, in order that the electrical means may be fully sealed, the mounting of the plates 62 and IE1 across the face of the recess 68A is accomplished in such a manner as to effectually seal the chamber 60A. Thus a suitable adhesive 0r sealing compound is placed between the plate I32 and the shoulder 6|, while such a compound is similarly placed between the abutting faces of the plate I0 and the plate 62. Thus when the two plates are secured in position by the action of the screws II, the border portion of the chamber 63A are properly sealed. It will also be recalled that the rivets that serve to secure the terminals 69 in place originally have openings therethrough, but in the course of connecting the wires to the terminals 69, the soldering at 69 serves to effectually close and waterproof these openings. The openings through which the rivets I III are extended are also sealed against passage of water and water vapor, and this is accomplished by application of a sealing compound or substance about the rivets IIlI and the terminals Hill and I62 when these elements are put in place. Thus the chamber 63A as Well as the chamber 50 are effectively sealed against the entry of water or water vapor.

In associating the connector cord 2I with the microphone device of the present invention, the end cap 36 is removed, thereby to expose the connecting arms of the terminals 69 so that the wires 2IA of the connector cord 2i may be connected as by soldering to the appropriate terminals 63. In this connection it will be observed that the end cap 35 has an axial opening I40 formed therein so as to surround one end of an externall threaded nipple MI that is secured as by spinning or staking the nipple in the lateral projecting arm of the bracket 63. The nipple MI has means screw threaded thereon for clamping the end cap 36 in position on the end of the casing 25, and in this connection it will be noted that the end cap 36 is so related to the other elements of the device that the terminal chamber 56 is sealed against water or water vapor when the end cap 36 is properly secured in position. Thus it will be evident in Fig. 7 of the drawings that an annular washer I44 of a resilient material is disposed against an annular 11 snugly fitting relation to the nipple HI, and this resilient washer I45 is clamped against the end wall of the cap 36 by a metallic Washer I51 and a clamping nut I43, the nut I48 being threaded on the nippl MI. The sealing gland also includes a clamping nut or member I50, and when the washers I46 and I41 and the nuts I53 and I55 are removed, the end cap may be removed by endwise withdrawal along the axis of the nipple MI. The gland 16 utilizes the nut or threaded sleeve I to apply clamping and sealing pressure to the connector cord 2|, and for this purpose, the lower end of the nipple MI is reamed to afiord an inwardly tapering conical surface I52 against which an enlarged conical end portion I53 or a resilient sealing sleeve I54 is adapted to engage. The nut I55 is flanged inwardly at I55 to afford an angularly disposed shoulder upon which a metallic washer I56 is disposed. The

washer I56 engages an annular abutment shouln i der of the sleeve I54 so that by tightening the nut I55, the enlarged sealing end I53 of the sleeve I54 may be forced inwardly into the conical surface I52 of the nipple I4I. Thus the sealing portion I53 is compressed or contracted so as to clamp the cord 2| and effect a tight seal about the surface thereof, and this is accomplished without objectionable rotative movement of the sleeve I 54 and the connector cord 2 I. Thus twisting of the cord 2! with the consequent damage to the connections with the terminals 55 is avoided. The compression of the sealing sleeve I54 and the resultant clamping of the cord 2| serves to prevent endwise displacement of the cord.

At the other end of the casing 25, the end cap 35 is so associated with the casing 25 and with the microphone unit 4| that objectionable entry of water or water vapor into the chamber 45 is prevented. Thus it will be noted that the end cap 35 fits down over the upper end of the easing as viewed in Figs. '1 and 8, and the lower edge of the end cap 35 is arranged to rest upon a resilient annular sealing washer I65 that in turn bears upon an annular abutment shoulder I5! formed on the two sections of the casing 25. When the end cap 35 is thus positioned, it is held in a firml clamped relationship with respect to the sealing ring or washer I60 by a retaining ring I that is annular in character and which surrounds the side walls of the end cap 35. This retaining ring I55 has a plurality of set screws I55 extended therethrough, as will be evident in Figs. 4, 5, l0, l2 and 13, and these set screws are engaged with matching recesses I61 formed in the walls of the casing sections 25A and 25B. It will be observed in Fig. 12 that the casing section 25A has a relatively wide rib I59 formed longitudinally thereof opposite the grooves its, thereby to afford proper wall thickness adjacent these grooves, and the end cap 35 has a complemental rib I15 formed therein to embrace the rib I65. The outer surface of the securing ring IE5 is, however, truly annular in character, but the inner surface thereof is cut away as at I'II so as to provide clearance for the rib I10 of the end cap 35.

The mounting of the end cap 35 on the casing 25 serves also to hold the microphone unit M in position in the chamber 40, and the relationship of the parts is such that the chamber 55 is efiectually sealed against the entrance of water or water vapor. As will hereinafter be described in greater detail, the microphone unit 4| has a cap I15 that is formed of Bakelite or like material so as to overlie the diaphragm I16 of the microphone, and it is in the cap I15 that the sound-receiving openings 42 are formed. The diaphragm 515 is of a waterproof construction so as to iiereby protect the internal elements of the micro hone unit 4! against the entry of water and water vapor, and a sealed arrangement is afiorcied about the upper border portions of the cap I15 so that water or water vapor cannot pass into the chamber 411. Thus the cap I15 has a rib 515A about the area in which the openings 62 are formed, such rib Il5A being annular in character as will be evident in Fig. 10 of the drawings. When the microphone unit 4! is to be placed in the chamber 35, a cushioning pad I18 of rubber or other resilient material is placed in the bottom of the chamber 40 against the surface oi the wall 45, and in many instances it may be desirable to secure this cushioning pad in position by adhesive so as to insure against loss of the pad. The microphone unit 4| is moved ondwise into position in the chamber 45, and in the course of such movement the terminals I01 or the microphone unit are moved into operative o tagement with the spring terminals I05. The mounting operation thus described also moves the bottom of the microphone unit 4| into abutment with the pad I18, which, it will be noted, serves to insulate the unit from the rivets IIlI and the terminal brackets m2, and after this has been accomplished, a sealing washer I of rubber or like material is placed in such a position that it engages the upper edge of the flange I15A as well as the upper edges of the walls that define the chamber All. In this conenction it should be noted that the sealing washer ISO is of such a form that it extends onto the top of the rib I59, thereby to effectuall close the upper ends of the slots I55. I'he end cap 55 is then put into position and is forced downwardly so as to compress the lower sealing ring I50 and the upper sealing ring I89, there also being an incidental compression of the pad I18 which serves to hold the ledge 515A firmly against the sealing ring I80.

hus the chamber II is sealed against the entry of water or water vapor, and the electrical elements such as the terminals I05 are protected against any undesirable action that might result from the presence of such water or water vapor. When the two metallic end caps 35 and 35 are thus secured in place on opposite ends of the casing 25, they serve not only as additional means for preventing separation of the casing sections 25A and 2513, but also as a protecting means about the ends and end edges of the casing, and hence the end caps strengthen the assembly and prevent damage that might otherwise be caused by blows striking the ends of the device.

The clamping or fastening ring I55 also serves as a part or" the mounting means for removably securing the noise shield 23 in position on the microphone device, and as will be evident in Fig. 2 of the drawings, the noise shield 24 has a sleevelike portion E that surrounds the side Wall of the end cap 35, and this sleeve-like portion I85 has an internal groove I85 formed near one end thereof that embraces the securing ring I55, thereby to hold the sleeve-like portion in position on the microphone device. At the other end of the sleeve-like portion I85, the noise shield 23 includes a flared portion I88 having its end edges 538A formed in such a manner as to be adapted to embrace the surfaces of the users face about the mouth as shown in Fig. 1, thereby to exclude outside noise. The noise shield 23 has a plurality of pressure relief openings or passages I90 formed therein whereby air pressure within the noise shield 23 is relieved while entrance of objectionable noise from the outside is prevented.

It will be recognized that under the broad aspects of the present invention, the character or type of the microphone unit 4! as well as the noise shield 23 may take different forms, but as herein illustrated, the microphone unit 4| is so constructed and arranged that it is in effect complemental to the specific construction of the noise shield 23 insofar as frequency response characteristics may be concerned, and the joint action of the particular microphone unit 4| and the noise shield 23 is such as to produce a substantially flat frequency response curve throughout the normal range of speech frequencies. In the form that is herein illustrated, the microphone unit 4| is of the dynamic or moving coil type, and as shown in Figs. 14 to 18 of the drawings, this microphone unit comprises a cup-like outer shell or housing 200 having integral annular side Walls 2!". Adjacent the upper end of the side walls 20!, an internal annular shoulder 202 is provided, and above the shoulder 202, the wall 20! is relatively thin as indicated at 20|A in Fig. 15 of the drawings. The shoulder 202 is disposed in a plane parallel to the inner surface 204 of the bottom wall of the housing 200, and a cylindrical permanent magnet 205 is rested on the surface 204 of the bottom Wall so as to be concentric with the shoulder 202. The magnet 205 is preferably secured in position on the surface 204 by soldering the same to this surface as indicated at 206. The housing 200 is made from a soft iron material so that it constitutes a part of the magnetic circuit of the microphone, and the upper end of the magnet 205 constitutes the inner pole of the magnetic circuit, The outer pole of the magnetic circuit is provided by a soft iron pole plate 208 that has a central opening 209, Fig. 18, formed therein so as to be spaced from the magnet 205 and thereby afford an annular magnetic gap. The outer pole plate 208 is fitted into the upper end of the housing 200 so as to rest upon the shoulder 202, and. in order that an upward annular rim or ledge 208A may be afforded about the upper surface of the plate 200 for supporting the diaphragm H6 in a spaced relation to the plate 208, the plate 208 is formed or coined so as to be offset about its outer edge, thereby to also provide a rabbeted annular groove 208B about its lower outer corner. This rabbeted annular groove 208B fits over the shoulder 202.

Before the outer pole plate 208 is put in position in the housing 200, means are mounted within the annular space about the magnet 205 for controlling the response characteristics of the microphone, and in the present instance such means are relatively simple in character. Thus a molded washer-like member 2 l2 made from hard rubber or other moldable material is put in position about the magnet 205, and this member 2l2 serves to accurately define a back chamber and limit the volume of air that is trapped between the upper surface 2l2A of the member H2 and the lower surface of the outer pole plate 208.

After the outer pole plate 208 has been put into position, the diaphragm H6 is mounted in position so as to be supported upon the annular ledge 208A. In the form herein shown the diaphragm H6 is made in two parts from a waterproof material such as molded paper pulp having a waterproofing ingredient such as a thermo-setting resin included therein. The diaphragm I76 thus includes a substantially flat annular flexing porple and effective manner.

tion llGA, the outer border of which is seated upon and secured as by adhesive means to the upper face of the annular ledge 200 A. The inner edge of the annular flexing portion I 16A has a generally cylindrical portion [163 formed thereon in an integral relationship so as to afford a voice coil support. This cylindrical portion H613 has an annular offset or shoulder 1710C formed therein so that on the outer surface of the cylindrical portion IIGB, the offset l 160 affords a guiding shoulder against which one end of a voice coil 2l5 may be wound. The annular portion HGB is so disposed on the flexing portion I l'GA that the voice coil 2|5 is disposed within the annular magnetic gap formed between the surface 209 and the magnet 205. After the flexing portion USA has been secured in position on the annular ledge 208A in a properly centered relationship which centers the voice coil with respect to the axis of the magnetic gap, a dome portion lliiD having a cylindrical flange IIGE at its outer edge is inserted into the cylindrical portion I'IGB, and such inserting movement is limited by engagement of the flange E with the offset l 10C. The dome l'lBD is of course secured by a waterproof adhesive in the position that is thus determined by the offset W6C, and thus the waterproof diaphragm is completed.

The ends 2 l 5A of the voice coil 2 l 5 are extended upwardly through the flexing portion 116A of the diaphragm in a sealed Waterproof relation there being a waterproof substance applied to the wires and the diaphragm at the points where the wires extend through the diaphragm, and the wires are then extended outwardly in a generally radial direction along the upper surface of the flexing portion and are secured thereto by adhesive means. The outer ends of the wires 2 l 5A are extended substantially beyond the edge of the flexing portion 116A for connection with the terminals l0! as will now be described. The terminals I01 are mounted in an outwardly extending terminal block portion 15B of the cap I15, and provision is made for extending the wires 245A outwardly beneath the edge of the cap H5 in a sim- Thus it will be noted in Figs. 15 and 18 of the drawings that the cap I 15 has an outward extension or flange 220 about its edge and this flange has a downwardly extending annular flange 22! formed at its outer edge. The cap I75 is inserted in the upper end of the wall 20IA so that the flange 22] bears upon the border portion of the diaphragm to hold the same down against the ledge 208A, and it will be observed that the radially projecting terminal block I15 extends through a slot 223 formed in the rim orupper edge of the wall 20! A. After the cap has been put in position as just described, the upper edge of the wall we is flanged inwardly as indicated at 225 so as to overlie the flange 220 of the cap H5 and thus the cap H5 is held in position. It will be observed that when the cap is in this position, the downwardly extending flange 22! on the cap provides an appreciable clearance space 225 above the flexing portion of the diaphragm 116. In extending the wires 2|5A outwardly for association with the terminals I01, it should be observed that downwardly facing notches 230 are formed in the flange 22! and these notches extend outwardly into vertically extending grooves 23l formed in the outer face of the terminal block portion 1153. These vertical grooves extend upwardly so as to enter the respective bores 233 in which the shanks 101A. of the terminals I0! are to be driven. Thus when the wires ZIEA are led outwardly through the notches 230, they are then extended upwardly through the grooves 231 and are wound about the respective shanks of the terminals l! which are at this time partially inserted into the bores 233. The wires may then be soldered to the shanks if desired, after which the terminals lill are driven completely into the bores 233, such inward movement being limited by enlarged spacing shoulders IDIB formed on the terminals I01.

The microphone device of the present invention is normally shipped in completely assembled relationship so as to include a connector cord 2! in an operative relationship to the device, and hence the initial association of the microphone device with a transmitter or the like is accomplished merely by establishing he desired connection between the other end of the connector cord and the equipment with which the device is to be used. In the use of the device the operator may rely upon the self-orienting characteristics of the microphone as afiorded by the present invention, and when the microphone device is to be used, the operator merely grasps the elongated body of the device in the manner shown in Fig. 1 of the drawings. When the body of the microphone device has been encircled by the hand of the user, the switch operating means 24 are invariably in such a position that they may be readily operated merely by a squeezing action of the users hand. In the course of the movement of the device from the floor or other location where it has been positioned during an idle period, the retarding action of the cord 2| as the operator lifts the microphone toward his face serves to cooperate with the elongated form of the microphone device to indicate which end of the device constitutes the sound-receiving end thereof, and hence, by the time the device has been moved relatively close to the users mouth, the user will know which end of the device is to be moved into operative relationship with respect to the mouth. It will be clear therefore that as soon as the microphone device has been moved relatively close to the mouth of the user, it will invariably be possible for the user to locate the microphone device in a proper position so that transmission may start immediately. The fact that the switch operating means 24 is at this moment invariably positioned so that it may be operated also contributes to the efficiency of operation that may be attained with microphone devices constructed under the present invention. The characteristics of the switch operating means 24 of the present invention that enable this switch operating means to be actuated by a squeezing action of the hand also impart to the present microphone device an added range of usefulness, for it will be apparent that the switch operating means 24 may readily be operated even though the user may be wearing relatively heavy gloves.

The microphone device of the present invention is also capable of being serviced in a relatively easy and efiicient manner, and this may be accomplished without disturbing the sealed relationship of the electrical elements that are disposed within the mounting chamber 50. Moreover, it will be evident that the microphone unit 3! may be removed and replaced in a relatively simple manner and this may be accomplished Without disturbing the sealed relationship of the terminal chamber 56. Furthermore, the connector cord may be readily replaced by opening the terminal chamber 56, and this may be accomplished without disturbing the sealed relationship of the microphone M. The servicing operations in respect to the connector cord 2| are materially simplified through the novel and efiicient action of the sealing gland 16 which not only clamps the connector cord 2! but also produces the desired seal about the cord so as to prevent entry of water or water vapor. The sealing and clamping action that is thus accomplished by the gland I6 is effected in such a way that objectionable rotative movement of the cord is avoided, and this, taken in connection with the clamping action that is exerted on the cord 2| serves to prevent undesirable stresses upon the connections that have been established between the wires ZIA and the terminals 59.

From the foregoing description it will be evident that the present invention materially simplifies the problem of attaining rapid and efficient transmission wih microphones of the hand-held.

type, and it will also be evident that the microphone unit of the present invention is in effect self-orienting so as to enable the microphone to be readily grasped and used for transmission purposes when this is required. The hand-held microphone device of the present invention is of such a character that it may be supported in the desired operative relationship to the users month without placing the hand and arm of the user in an unnatural or strained relationship, and because of this, the microphone device of the present invention may be used for relatively protracted periods without undue strain or fatigue.

It will also be evident that the hand-held microphone device of the present invention attains an effective sealing of the electrical elements thereof in a simple and highly effective manner; and it will be clear that this sealing action is attained in such a way that the normal servicing operations that must be performed upon devices of this character may be accomplished without disturbing the sealed relationship of most of the elements of the device.

The hand-held microphone device of the present invention also materially simplifies the operation of switch means that are in some instances associated with hand-held microphone devices, and in accordance with the present invention, such switch means may be readily and easily operated as soon as the user has grasped the device in the normal manner.

Thus, while we have illustrated and described the preferred embodiment of our invention, it is to be understood that this is capable of variation and modification and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. In a hand-held microphone device, an elongated sectional body comprising a pair of elongated sections separable in a plane extending substantially through the longitudinal axis of said body, said sections at one end thereof being formed with matched cavities defining a first chamber opening longitudinally of the body through said one end thereof, said sections of said body having matched main cavities therein spaced from opposite ends thereof and defining a main chamber, switch means mounted in the main cavity of one of said sections, a transformer mounted in said main cavity of said one section, the other one of said sections having an opening formed therethrough and facing toward said switch means, a flexible waterproof sheath extended outwardly through said opening and having flanges thereon engaged with an inner surface of the main cavity in said other member about the inner borders of said opening, a switch operating member movably supported within said sheath and acting to urge said sheath into a projecting relationship with respect to the outer surface of said body, means forming an operative connection between said switch operating member and said switch means whereby inward movement of said sheath and said switch operating member serves to operate said switch means, means affording a sealed relationship between the fiange of said sheath and the surface of said cavity with which it is engaged, means in said one of said sections of said body member affording a connecting chamber opening through one surface of said one of said sections, connecting wires extended from said switch means and said transformer and from said main chamber into said connecting chamber, a mounting bracket surrounding the open side of said connecting chamber and having a connecting opening therethrough, an insulating terminal plate covering said connecting opening in said mounting bracket, terminals extended in waterproof relation through said terminal plate and connected to the respective ones of said wires within said connecting chamber, means securing said terminal plate and said mounting bracket in a waterproof relationship across said open side of said connecting chamber, a screw threaded connector nipple mounted in a rigid relationship on said mounting bracket, a cup-shaped end cap having an opening therein to embrace said nipple, means on said sections of said body affording a continuous shoulder facing end wise toward said other end of said body, said nipple having its axis disposed coaxially with said shoulder, a resilient sealing ring disposed against said shoulder, said cupshaped end cap having its open end edges disposed against said resilient sealing ring, a nut disposed on said nipple, a resilient sealing ring disposed between said nut and said cup-shaped end cap to afford a seal about said nipple, means associated with said nipple for affording a seal about a connector cord when such a cord is extended through said means and said nipple, and means affording a perforated end cap for said one end of said body to house and protect a microphone unit disposed in said first chamber.

2. In a hand-held microphone device, an elongated sectional body member comprising a pair of elongated sections separable in a plane extending substantially through the longitudinal axis of said body member, said sections at one end thereof being formed. with matched cavities defining a first chamber opening longitudinally of the body through said one end thereof, said sections of said body having matched cavities therein spaced from opposite ends thereof and defining a main chamber, switch means mounted in the cavity of one of said sections, a transformer mounted in said cavity of said one section, the other one of said sections having an opening formed therethrough and facing toward said switch means, a switch operating member movably supported in said opening and operatively related to said switch means whereby inward movement of said'switch operating member serves to operate said switch means, resilient means affording a sealed waterproof relationship between said member and the section in which it is mounted, means securing said sections together to seal said main chamber, terminal means on said one of said sections of said body member, and means including connecting wires extended from said switch means and said transformer to said terminal means in a waterprof relationship,

3. In a hand-held microphone device, an elongated sectional body member comprising a pair of elongated sections separable in a plane extending substantially through the longitudinal axis of said body member, said sections at one end thereof being formed with matched cavities defining an end chamber opening longitudinally of the body through said one end thereof, said sections of said body having matched cavities therein spaced from opposite ends thereof and defining a main chamber, switch means mounted in the cavity of one of said sections, a transformer mounted in said cavity of said one section, the other one of said sections having an opening formed therethrough and facing toward said switch means, a flexible waterproof sheath extended outwardly through said opening and having flanges thereon engaged with an inner surface of the cavity in said other member about the inner borders of said opening, a switch operating member movably supported within said sheath so as to urge said sheath into a projecting relationship with respect to the outer surface of said body, means forming an operative connection between said switch operating member and said switch means whereby inward movement of said sheath and said switch operating member serves to operate said switch means, means affording a sealed relationship between the flange of said sheath and the surface of said cavity with which it is engaged, terminal means on said one of said sections of said body member and means including connecting wires extended in a waterproof relationship from said switch means and said transformer to said terminal means.

4. In a hand-held microphone device, a housing having a central chamber sealed against the entrance of water and water vapor and affording a secondary chamber at one end of said sealed chamber and connecting chamber at the other end of said sealed chamber, said secondary chamber having a pair of contact terminals therein, a microphone unit disposed within said secondary chamber and having contact terminals engaging said first mentioned terminals, a releasable cap member engaging said microphone unit and releasedly retaining the same in said secondary chamber, an impedance matching transformer and switch means mounted within said sealed chamber, said transformer having primary and secondary windings one of which is electrically connected at its opposite ends to said stationary terminals, connections including wires extended from the ends of the other winding of said transformer and at least one of said last mentioned wires being connected through said switch means, a terminal plate forming a wall of said connecting chamber and having connecting terminals extended therethrough, said last mentioned connections being extended to the inner sides respectively of said connecting terminals, an end cap having an opening therethrough and enclosing said terminal plate and defining a terminal chamber including said connecting terminals, and means associated with said end cap for affording a seal about a connector cord when such a cord is extended into said end cap for association with said connecting terminals.

5. In a hand-held microphone device, an elongated. sectional casing comprising matched sections separable along a-longitudinally extended plane of separation, said sections having opposed recesses formed therein to open through the matched faces thereof to afford a mounting chamber, a microphone unit mounted at one end of said casing, switch means mounted in the cavity in one of said sections and operatively connected to said microphone unit for governing operation thereof, and a switch operating element movably mounted on the other of said sections in position to be operatively related to said switch means as an incident to the positioning of said sections in matched opposing relationship.

6. In a hand-held micrphone device, an elongated sectional casing comprising matched sections separable along a longitudinally extended plane of separation, said sections having opposed recesses formed therein to open through the matched faces thereof to afford a mounting chamber, a microphone unit mounted at one end of said casing, switch means mounted in the cavity in one of said sections and operatively connected to said microphone unit for governing operation thereof, terminal means on 'said one section arranged to be disposed in an exposed relation when said sections are assembled, a switch operating element movably mounted on the other of said sections in position to be operatively related to said switch means as an incident to the positioning of said sections in matched opposing relationship, and a cup-like end cap secured to said casing in surrounding relation to said terminal means.

"7. In a hand-held microphone device, an elongated sectional casing comprising matched sections separable along a longitudinally extended plane of separation, said sections having opposed recesses formed therein to open through the matched faces thereof to afford a mounting,

chamber, a microphone unit mounted at one end of said casing, switch means mounted in the cavity in one of said sections, means operatively connecting said switch means to said microphone unit in a waterproof relation for governing operation thereof, terminal means on said one section arranged to be disposed in an exposed relation when said sections are assembled, means including wires extended from said mounting chamher to said terminal means in a waterproof relation, a switch operating element movably extended in a waterproof relation through a Wall of said mounting chamber and operatively related to said switch means for actuating the same,

means securing said sections together to seal said mounting chamber against water and water vapor, and a cup-like end cap secured to said casing in surrounding relation to said terminal means.

8. In a hand-held microphone device, an elongated sectional casing comprising matched sections separable along a longitudinally extended plane of separation, said sections having opposed recesses formed therein to open through the matched faces thereof to afford a mounting chamber, a microphone unit mounted at one end of said casing, switch means mounted in the cavity in one of said sections and operatively connected to said microphone unit for governing operation thereof, said other section having an opening formed therethrough from said recess, a switch operating member extended through said opening in position to be operatively associated with said switch means as an incident to assembly of said sections, a flexible waterproof sheath covering the exposed surfaces of said member and having border portions thereof secured to said other section about said securing said sections together in a sealed and waterproof relation to keep water and water vapor out of said chamber.

9. In a hand-held microphone device, an elongated sectional casing comprising matched sections separable along a longitudinally extended plane of separation, said sections having opposed recesses formed therein to open through the matched faces thereof to afford a mounting chamber and also to define an end chamber adjacent one end of said mounting chamber and opening through the adjacent end of the casing, a microphone unit mounted in said end chamber and having a waterproof diaphragm, switch means mounted in the cavity in one of said sections, means including wires extended in a waterproof relation between said chambers and operatively connecting said switch means to said microphone unit for governing operation thereof, said other section having an opening formed therethrough from said mounting chamber, a switch operating member extended through said opening in position to be operativel associated with said switch means as an incident to assembly of said sections, flexible waterproof sheath covering at least the outer surfaces of said memher and having border portions thereof secured to said other section about said opening in a waterproof relation, means securing said sections together in a sealed and waterproof relation to keep water and water vapor out of said chamher, an end cap with a centrally perforated end wall and an imperforate border portion in said end Wall about the central perforated portion, a resilient sealing Washer within said end cap and engaging said imperforate portion of said end cap, the end edges of said casing about said end chamber and said microphone unit near the edge portions of the diaphragm thereof, and means securing said end cap on said casing to compress said sealing washer between the parts engaged thereby.

19. In a hand-held microphone device, an elongated casing having a waterproof mounting chamber formed therein and also having an end chamber adjacent one end of said mounting chamber and opening through the adjacent end of the casing, a microphone *unit mounted in said end chamber and having a waterproof diaphragm, switch means mounted in said mounting chamber, means including wires extended in a waterproof relation between said chambers and operatively connecting said switch means to said microphone unit for governing operation thereof, said casing having an opening formed therethrough from said mounting chamber, a switch operating member extended through said opening in position to be operatively associated with said switch means, a flexible waterproof sheath covering at least the outer surfaces of said member and having border portions thereof secured to said casing about said opening in a waterproof relation, an end cap with a centrally perforated end wall and an imperforate border portion in said end wall about the central perforated portion, a sealing washer within said end cap and engaging said imperforate portion of said end cap, the end edges of said casing about said end chamber and said microphone unit near the edge portions of the diaphragm thereof, and means securing said end cap on said casing to compress said sealing washer between the parts engaged thereby.

11. Ina hand-held microphone device, an elongated casing comprising a pair of elongated separable sections disposed with their parting faces in opposed relation and having matched cavities affording an elongated main chamber defined at one end by an end wall and at its other end by a relatively thick division wall, and also affording an end chamber adjacent to and defined on one surface by said division wall and opening through the adjacent end of said casing, means including a fastening element extended into said division wall and securing said sections together to prevent entry of water and water vapor into said main chamber along said parting faces of said sections, one of said sections having an integral extension formed. thereon so as to extend longitudinally beyond said end wall, and the other of said sections terminating at said end wall so as to thereby leave the parting face of said one section exposed throughout the length of said extension, said extension having a recess formed therein and opening laterally through said parting face of said extension, said one of said sections having a passage therein connecting said recess and said main chamber, a terminal plate having terminals disposed on one face thereof and having conductors disposed on and extended from the other face thereof and connected in a waterproof relation to said terminals, means including an angle bracket securing said terminal plate in a waterproof relation across the open face of said recess with said conductors enclosed within said recess and with said terminals exposed, said bracket having an arm disposed normal to said parting face, a threaded nipple secured on said am and disposed on the longitudinal axis of said casing, a cup shaped end cap surrounding and protecting said extension and said terminals, said casing having a continuous shoulder formed thereon and in opposed relation to the edge of said end cap, a compressible sealing washer disposed on said shoulder for engagement by said edge of said end cap, means including another sealing washer and a clamping nut surrounding said nipple and clamping said cup in position with said sealing washers in sleeve, a microphone unit mounted in said end chamber and having a waterproof diaphragm, switch means mounted in said main chamber, means including other conductors extended in a Waterproof relation between said chambers and also including said first mentioned conductors and operatively connecting said switch means to said terminals and said microphone unit for governing operation thereof, said casing having an opening formed therethrough from said main chamber, a switch operating member extended through said opening in position and operatively associated with said switch means, a flexible Waterproof sheath covering at least the outer surfaces of said member and having border portions thereof secured to said other section about said opening in a waterproof relation, a second end cap with a centrally perforated end wall and an imperforate border portion in said end wall about the central perforation portion, another sealing washer within said second end cap and engaging said imperforate portion of said end cap, the end edges of said casing about said end chamber and said microphone unit near the edge portionsof the diaphragm thereof, and means securing said second end cap on said casing to compress said last mentioned sealing washer between the parts engaged thereby.

WEBSTER E. GILMAN. RAYMOND C. BIERMAN.

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